Track link connector

ABSTRACT

A track chain connecting link, especially clamping connector, which comprises a slot interconnecting the two chain bolt bearing eyes and extending along the plane passing through the two central axes of the bearing eyes while extending over the entire width of the connecting link which slot is compressible by means of a clamping screw, the track link connector consisting of steel being induction hardened at the circumference within the area of the interengaging portions of the driving rim approximately circularly over a depth of a few millimeters and approximately by 45 HRc so that the surface hardness remains maintained at least by 50 HRc.

O Unlted States Patent m13,594,04s

[72] Inventors Otto Kiirner; R f r n Cited [2]] App!v No. 827,544

- 2,957,731 10/1960 Backhaus 305/58 UX [22] Filed May 26, 1969 [45]Pammcd July 3,227,586 1/l966 Spencer..... 148/46 [73] Assign Diem3,340,717 9/1967 Korner 305/58 UX Numberg, Germany PrimaryExaminer-Richard]. Johnson [32] Priority June 1, I968 Attorney-WalterBecker [33] Germany [31] P17556303 ABSTRACT: A track chain connectinglink, especially clamping connector, which comprises a slotinterconnecting the two chain bolt bearing eyes and extending along theplane passing through the two central axes of the bearing eyes whileextend- {541 TRACK LINK CONNECTOR ing over the entire width of theconnecting link which slot 1 Claim 2 Drawing Figs. compressible by meansof a clamping screw, the track lin connector consisting of steel beinginduction hardened at the [52] US. Cl 305/58 circumference within thearea of the iriteren'gaging portions of [51] Int. Cl..... B6211 55/28the driving rim approximately circularly over a depth of a few [50]Field of Search 305/36, 58, millimeters and approximately by HRc so thatthe surface 59 hardness remains maintained at least by HRc.

PATENTED JUL 20 Ian INVENTOR. OTTO KQRNER AND ROLF MULLER TRACK LINKCONNECTOR The present invention relates to a track link connectingmember, especially a clamping connector, which has a slotinterconnecting the bearing eyes for the chain bolts and extendingapproximately along the plane passing through the central axes of saidbearing eyes while extending over the total width of the connectingmember. More specifically, the present invention concerns a track linkconnector in which the said slot can be compressed by a clamping screwagainst the spring effect or thrust of the connecting member.

With track chains it is highly disadvantageous that in the course oftime the teeth of the driving rim work themselves into the connectorwhich is designed as a follower. For purposes of controlling the wearand for indicating the maximum limit of admissibility, it is known toprovide the circumference of the track link connecting member withmarkings in the form of depressions and to provide these markings whichmay be colored, at the admissible limit of wear in the area where theconnecting member is engaged by the driving sprocket. In order toeliminate the drawbacks inherent to the wear as far as possible, it isalso known to keep those sides of the track link follower which face thedriving sprockets, during the movement of the track chain onto thedriving sprockets, at a certain distance from the bottom of the teeth ofthe driving sprockets. This is done by providing layers enveloping thewheel drum and/or by an inner supporting surface of the individual trackchain links which surface protrudes beyond the limit line of thefollower which faces the driving wheels.

The first mentioned solution indicates the degree of wear whereas thesecond indicated solution decreases the drawbacks inherent to wear.However, neither one of these solutions eliminates the source of error,namely wear itself.

It is, therefore, an object of the present invention to provide a trackchain connecting link which will overcome the abovementioned drawbacks.

It is another object of this invention to provide a connecting link asset forth in the preceding paragraph, which will reduce the wear to aminimum or even eliminate it all together.

These and other objects and advantages of the invention will appear moreclearly from the following specification in connection with theaccompanying drawing, in which:

FIG. 1 is a side view of a clamping connector according to the inventionwith partially hardened areas.

FIG. 2 is a top view of the hardened zone as seen in the direction ofthe arrow II.

The above-outlined objects have been realized according to the presentinvention by hardening the track link connecting member which consistsof steel at the circumference of the connecting member within the areaof engagement with the driving sprocket. The hardening is preferablyeffected by induction hardening over an approximately circular area upto a maximum depth of a few millimeters to approximately 45 I-IRc sothat a surface hardness of at least 50 I-IRc will be obtained.

In this way the hardening zone is, in conformity with the 7 higheststress occuring in said zone, preferably so selected that 3 and 4 havethe shape of segments 6 of a circle with a straight engaging side 7.While an upper part 8 of the connector main body is countersunk, a thicklower transverse member 9 is provided with inner thread 10 for theclamping screw 2.

The connecting links of connector track chains form driving transmissionelements from the driving sprocket to the chain. The outer lower sidesmesh with the driving sprocket which means remain i n permanentfrictional contact therewith. The teeth of the driving sprocket Willthus not beat Into the connector main body 1. In conformity with thepresent invention, the surface of the connecting link 1 is at the areasdesignated with the reference numeral 11 induction hardened and at thesurface at least to from to like. In the center the hardening partiallyextends, to a depth of a plurality of mi]- limeters. At a depth of 3millimeters locally, it should still amount to approximately from 40 to45. As has been indicated in FIG. 1 in connection with the inner limitof a hardening course, the hardening depth, starting from the center,decreases toward the marginal areas. The central axes of thesubstantially circular hardening zones l1, 12 are relative to the axisof the clamping screw 2 offset toward the left or the right from 30 to45, said axes passing through the center C of the circle of the radiusr.

It is, of course, to be understood that the present invention is, by nomeans, limited to the specific example shown in the drawing but alsocomprises any modifications within the scope of the appended claims.

What we claim is:

l. A track chain connecting member forming a link for engagement with adriving sprocket, comprising: a main longitudinal body having roundedsprocket engaging end portions, two bearing eyes spaced longitudinallyand connected by a transverse slot through said body, clamping screwmeans transverse to said link and slot and operable to contract saidslot, said track chain connecting member being partially surfacehardened locally at the rounded sprocket engaging end portions, eachhardening zone including an area having a central axis extending at anangle of 30 to 45 to the axis of said clamping screw means, each of saidhardening zones having a depth of a few millimeters along said axis anddecreasing toward its marginal areas with a hardness of 45 I-IRc at saiddepth and a surface hardness of at least 50 I-IRc.

1. A track chain connecting member forming a link for engagement with adriving sprocket, comprising: a main longitudinal body having roundedsprocket engaging end portions, two bearing eyes spaced longitudinallyand connected by a transverse slot through said body, clamping screwmeans transverse to said link and slot and operable to contract saidslot, said track chain connecting member being partially surfacehardened locally at the rounded sprocket engaging end portions, eachhardening zone including an area having a central axis extending at anangle of 30* to 45* to the axis of said clamping screw means, each ofsaid hardening zones having a depth of a few millimeters along said axisand decreasing toward its marginal areas with a hardness of 45 HRc atsaid depth and a surface hardness of at least 50 HRc.